Chapter 141:22Laws of the Megillah

22. On the morning [of Purim], it is customary to come to the synagogue
early. After the "Shemoneh Esrei" (1), a half-Kaddish is recited and the
passage beginning "Va'yavo Amalek" (Exodus: 17:8-16) is read from the
Torah. Three men are called up for the reading. A half-Kaddish is then
recited, and after the Torah scroll is returned to the ark, the Megillah is
read. In the morning, the passage "Asher Heini" is not recited, rather,
after the blessing "Ho'el Hamoshi'a", the passage "Shoshanas Ya'akov" is
recited instead. Afterwards, "Ashrei," U'vo leTzion" (2) and a full Kaddish
are recited. One should not remove one's Tefillin until after the reading
of the Megillah because [the Talmud in Megillah 16b] interprets the
word "V'yikar" ["and glory" from Esther 8:16: "And the Jews enjoyed light,
happiness, rejoicing, and glory"] as a reference to Tefillin. If there is a
child to be circumcised, he should be circumcised before the reading of the
Megillah, because the word "rejoicing" [in the above verse] is interpreted
as a reference to the mitzvah of circumcision (3).

FOOTNOTES:

(1) We do not recite Hallel on Purim; the Talmud reasons that on Pesach it
is appropriate to recite the verse from Hallel, "Hallelu Avdei Hashem"
("Sing praise, O' servants of G-d") because we were transformed from being
servants of Pharaoh into servants of Hashem, however, on Purim, even though
we were saved from Haman's murderous plot, we still remained servants of
King Achashverosh (Mishna Berura 693:7).

(2) We do not recite the Psalm beginning with "La'menatzeach"
between "Ashrei" and "U'vo Le'tzion" because it contains the word "tzarah"
("hardship") which is not appropriate to mention on Purim (Ibid 693:8).

(3) There are authorities who rule that the Megillah should be read before
the circumcision (Ibid 693:12).